Safety-switch interlock



- March 1-8 ,-1924.-

III II/ I H G BAXTER SAFETY SWITCH immmocx Filed Nov. 20, 1919WITNESSES:

- INVENTOR} Harald dflaxzer Patented Mar. 18, 1924.

UNITED STATES PATENT OFFICE.

HAROLD G. BAXTER, OF BALDWIN, NEW YORK, ASSIGNOR, BY MESNE ASSIGNMENTS,TO WESTINGHOUSE ELECTRIC 6t MANUFACTURING COMPANY, A CORPORATION OFPENNSYLVANIA.

SAFETY-SWITCH INTERLOCK.

Application filed November 20, 1919. Serial No. 339,258.

To all whom it may concern:

Be it known that I, I'IAROLD G. BAXTER, a subject of the King ofEngland, and a resident of Baldwin, in the county of Nassau and State ofNew York, have invented a new and useful Improvement in Safety-SwitchInterlocks, of which the following is a specification.

My invention relates to safety switchboards and particularly to safetyswitch boards of the dead-front type.

one object of my invention is to provide a dcad-front switch-board thatshall have an operating handle mounted on the front face of its panelfor actuating the switches that are mounted at the rear thereof and thatshall also have a fuse-box at the rear of the panel provided with a doorso interlocked with the handle, that an attendant must so actuate thelatter, as to open the switches before the fuse-box door may be opened,and, moreover, the attendant must close the fuse-box door before thehandle may be operated by him, to close the switches.

A further object of my invention is to provide a dead-front switch-boardthat shall be simple and rugged in construction and safe in operation.

In practicing my invention, I provide an operating handle on the frontof a switchboard panel to actuate a plurality of switch members at therear thereof, by means of a rod passing through the panel. The switchmembers are adapted to introduce, into an electrical circuit, aplurality of fuses, that are contained in a closed box on the rear ofthe panel, I provide further, an interlocking mechanism which is sodisposed, that the rod, which is actuated by the handle, is preventedfrom actuating the movable switch members when the fuse-box door isopen, and the door is so interlocked with the switch-operating mechanismthat it may not be opened when the switch members have the fusesconnected in th circuit. The interlocking mechanism is enclosed in areceptacle within the fuse-box.

Figure 1 is a side view, partially in section, and partially inelevation of a switchboard embodying my invention; Fig. 2 is a view,from the rear of the switch-board, of the interlocking mechanismembodied in the fuse-box illustrated in Fig. 1; and Fig.

3 is a top plan View of the fuse box, illus 'trating the arrangement ofan actuating rod 'of is mounted a fuse box 3, that encloses a pluralityof fuses 1 and a receptacle 5, in which an interlocking mechanism 6 isdisposed. An actuating rod 7 extends from the operating handle 2,through an opening in the panel, into the fuse-box 3 and through thereceptacle 5. The end of the rod 7 that is in the fuse-box is bent at aright angle to its body portion and is provided with a hole 10 toreceive a pin 8 with which the door 9 of the fuse-box 3 is provided. Theinterlocking mechanism 6, that is en closed in the receptacle 5,comprises slidably mounted auxiliary rod 11 having a spring 12 mountedthereon, a latch 13, that is pivotally mounted on a'pin 1 1, a, link 15that connects the auxiliary rod 11 to the latch 13 and a lateralprojection 16 on the actuating rod 7. Switch members 17 are adapted tobe actuated by the rod 7 to connect, electrically, a plurality of fuseterminals 18 to a bus-bar 19. A manually operated latch 20 is slidablymounted in a guideway 21 and comprises a body member 22 that has the pin8 mounted as a lateral projection thereon, a spring 23 for returning thelatch 20 to a predetermined position and a handle 24 for so actuatingthe latch 20 that the door 9 may be opened.

As illustrated in Fig. 1, the switch. unit is shown closed, with theoperating handle 2 in a position corresponding to that of an ordinaryknife-blade switch when the switch is closed. The door 9 of the fuse-box3 is closed and cannot be opened while the switch is in its closedposition by reason of the engagement of the pin 8 with the hole 10 inthe end of the rod 7. If the switch unit is in its opened position, andthe door 9 is opened, the auxiliary rod 11, which is ordinarily held inby the door 9, will be forced out by the spring 12. The latch 13 is thenturned about the pivot 14 by the link 15 to engage the projection 16 onthe rod 7. The rod 7, therefore cannot be actuated by the operatinghandle 2 so long as the door 9 is open. When the door 9 is closed, theauxiliary rod 11 is forced back into place against the compression ofthe spring 12, and the latch 13 is withdrawn from the projection 16 onthe rod 7, thus permitting the rod 7 to more again.

Although my invention is shown in a preferred form, I do not wish tolimit the invention to the structure shown, as various modifications maybe made without departing from the spirit and scope of my invention asset forth in the appended claims.

I claim as my invention:

1. In a dead-front switch-board, the combina ion with an operatinghandle on the front of its panel and a fu -box at the rear of the panelhay in p; adoor, 0 fuses, an electric circuit associated therewith,movabl switch members in the circuit adap ed to introduce the fuses intothe circuit, a rod member adapted to be actuated by the operating handleto actuate the movable switch members when the fuse-box door at the rearof the panel is closed, means for latching said rod in open positionwhen the fuse-box door is open to preclude the introduction of the fusesinto the circuit, and manually operable latch means associated with theswitcw actuating rod for precluding the opening of the fnse box door ifthe switch is closed.

2. In a dead-front switchboard, the combination with an operating handleon the front of its panel and a fuse-box at the rear of the panel havinga door, of fuses, an electric circuit associated therewith, switchmembers in the circuit adapted to introduce the fuses into the circuit,means for precluding the opening of the fuse-box door when the switch isclosed, and yielding means controlled by the door for precluding theactuation of the operating handle when the fuse-box door is open.

3. In a switchboard, the combination with a handle on the front of itspanel, and a fuse-box having a door thereto at the rear of the panel, offuses, a circuit associated therewith, switch-connecting members for thefuses and the circuit, a rod member sociated with the handle foractuating the switch-connecting members, a perforated end member on therod member, a pin member mounted on the door of the fuse-box, said pinmember being adapted to so engage the end member, that the door may notbe opened if the fuses are connected to the circuit, a latch member, anauxiliary rod member, and a link member connecting the latch member andthe auxiliary rod member, a resilient member'so associated with theauxiliary rod member as to actuate said rod member when the door isopened to turn said latch member by means of the. link member to aposition wherein the actuating rod is so latched that said rod may notbe actuated by the operating handle to introduce the fuses into thecircuit.

4-. In a dead-front switch board, the com bination with an operatinghandle on the front of its panel and a fuse box at the rear of the panelhavinga door, of fuses, an electric circuit associated therewith, switchmembers in the circuit adapted to introduce the fuses into the circuit,a latch for the door, means associated with the handle for preventingopening movement of the latch when the handle is in closed position andmeans controlled by the door for locking the handle in opcn positionwhen the door is moved to open position.

In a dead-front switch board, the COI11- bination with an operatinghandle on the front of its panel and a fusc box at the rear of the panelhaving a door, of a morable switch member, means associated with thehandle for actuating the movable switch member when the fuse box door isclosed and a manually operable latch for the door and controlled by thesaid means for retaining the door in closed position so long as theswitch is in closed position.

6. In a dead-front switch board, the combination with an operatinghandle on the front of its panel and a fuse box at the rear of the panelhaving a door, of a movable switch member, means associated with thehandle for actuating the movable switch member when the fuse box door isclosed and means controlled by the door normally tending to lock thesaid means against clos ing movement and held out of locking posi tionby the door when the door is in closed position.

7. In a dead-front switch board, the combination with an operatinghandle at the front of its panel and a fuse box at the rear of the panelhaving a door, of a movable switch member, means associated with thehandle for actuating the movable switch member when the fuse box door isclosed and means for locking the switch in open position operable fromthe rear of the panel and independently of the cover for releasing theswitch.

8. In a dead-front switch board, the com bination with an operatinghandle at the rout of its panel and a fuse box at the rear of the panelhaving a door, of a movable switch member, means associated with thehandle for actuating the movable switch member when the fuse box door isclosed, means for locking the switch in open position and means operablefrom the roar of the panel and independently of the cover for releasingthe locking means.

In testimony whereof, I have hereunto subscribed my name thistwentyseventh day of October 1919.

HAROLD G. BAXIER.

